Wireless communications systems have experienced rapid growth and technological innovation in recent years. Society has accepted and in some cases become dependent upon wireless technologies such as cellular phones and pagers for daily personal and professional communications. This has become possible by continual advancements in microelectronics and power technologies, which have aided in decreasing the size, weight and cost of these devices while increasing functionality. Many industrial and commercial applications have come to deposit on wireless technologies as well. Factories, warehouses, retail establishments and service establishments (e.g., rental car agencies and utilities) have also come to depend on wireless technologies thereby enabling workers to be more productive and decreasing their overall costs. Inventory control stations, checkout or billing systems, pricing and labeling systems, automatic storage and retrieval systems and short-range employee communications systems are just a few examples of applications that benefit from wireless communications technology.
Wireless communication systems utilize several well-known components such as a receiver, transmitter and an antenna. The receiver and transmitter, hereafter referred to as a communications module or subsystem, powers, filters, modulates and de-modulates associated communications signals, wherein the antenna is employed to receive and broadcast these signals. Antennas may be manufactured from many conductive materials, and are constructed according to the frequency of signal that is being received and/or broadcast. For example, a communications device that is receiving or broadcasting in the 400 megahertz frequency range will need a longer antenna than a comparable communications device receiving or broadcasting in the 900 megahertz frequency range due to the wavelength of the signal. There are many methods for constructing antennas and attaching them to communications modules in practice today. Many manufacturer install an externally mounted flexible rod, or whip antenna on their communications systems. These may be hard-wired into the communications module, or they may be detachable through techniques such as a threaded base. Devices that do not require long-range communications may have an internally mounted antenna such as a length of wire or coaxial cable. These and other methods of antenna construction and installation within a communications module are widely practiced and accepted, but each has drawbacks that render these techniques less than optimal.
Externally mounted antennas extend into the atmosphere from the communications device on which it is installed. The result is often less than aesthetically pleasing and has functional ramifications as well. Because of the protrusion of the antenna from the main body of the product; it is easy to catch or “snag” the device on stationary objects. If the communications device is dropped or placed without care, the antenna is likely to be affected due to its exposed installation. Impacts such as this will, over time, have the affect of distorting or damaging the antenna, thus changing the operating parameters. This could include a decrease in effective range, changing the desired operating signal frequency, and intermittent operation. The externally mounted antenna also creates challenges in manufacturing, as the method used to mount this type of antenna generally requires more parts and more machining processes, both of which will add labor, complexity and cost to the system.
Internally mounted wire of coaxial cable antenna, hereinafter referred to as a cable antenna, mitigates some of the problems associated with the exposed installation of an external antenna, but creates other obstacles in the process. Depending on the operating frequency, the cable required could be many inches in length, which may cause difficulty in securely placing and fastening the cable antenna within the communications devices. Because of the highly flexible nature of cable antennas, it is difficult to uniformly place and fasten them in each communication device manufactured, thus operating differences from one communications device to another are common. Also, sudden movement of the communications device or impact with another object may displace the cable antenna from the desired mounted position, thus dramatically affecting the performance of the device. The manufacture of the cable antenna is generally a manual process, and thus control of the final operating parameters is less than optimal.
In view of the above problems associated with externally and/or internally mounted wire antennas, there is an unsolved need for a system and methodology to provide reliable, higher quality and lower cost communications devices to consumers.